The methodology instruments to proportion objects in art design and architecture have been used as tools for thousands of years. Our western culture assumes by default that the use of these tools is useful, necessary and recommended. This thesis is a detailed analysis of these instruments, their uses and possibilities throughout western history. We will also examine the causes that led to the identification of these tools as useful in the design process, deeply analyzing their effectiveness as design strategies. Finally, the potential future uses of the older instruments is detailed as well as an analysis of the possible new techniques which are profiled to become the design tools of the new century.